Process of reactivating purifying agents



Patented Feb. 15, 1927.

. UNITED STATES v 1,617,533 PATENT OFFICE- PAUL MAHLER,

PROCESS OF'REACTIVATING PURIFYING AGENTS.

No Drawing.

My present invention relates to processes for reactivating or revivifying decolorizing or purifying agents, such as are commonly used in the arts, for removing color, odor and objectionable impurities rom various solutions or liquids.

The invention is more especially useful in the treatment of spent activated carbons, whether used with or without filter aids.

A common process of revivification of spent activated carbon is similar to the general methods of their manufacture, namely, subjecting to intense heat followed b treatment with an acid and washing to ree the F excess acid.

7 It is-an object of my invention to revivify the decolorizing agent without acid or in tense heating and by a simple procedure requiring little time and no specialized apparatus or equipment and no particular skill of treatment, the resultant revivified product being of substantially the same order of efficiency as that heretofore revivified by the more elaborate acid and intense heating process.

- My process consists in treating with a gas, the partially or wholly spent decolorizing or purifying agent removed from the treated liquor, preferably until the mass will take up IIOJDOIB of the gas. Preferably, the gas is passed into a fluid mass of the purifying agent, until bubbles pass up from the surface of the mass. This completes the revivifying process and the wet mass may be re-used for its intended purpose as a decolorizing or purifying agent or, if desired, it may be previouslydried.

I have found that chlorine gas is highly efficient for the purpose in hand. With the use of less than 5 percent by weight of chlorine compared to the weight of purifying agent, the revivifying process is completed. 1 do not wish, however. to be confined to the use of chlorine, as I have found other common gases, such as sulphur dioxide to have a practical degree of efliciency for my pur- Misc. 1 In a preferred specific mode of carrying out the process, the gas treatment is applied to a spent or partially spent activated carbon in a state of creamyconsistency. Either sufficient liquid is decanted from-the decolorizing vat to leave a residue of the consistency noted, or where the decolorizlng agent is passed into a filter press, the called mass Application filed April 15,1926. Serial No. 102,808.

thereof is rendered fluid by the addition of on new Yonx, N. Y., assronon 'ro naaco SALES conroaa'rron, or NEW YORK, 1w. Y., A CORPORATION or DELAWARE.

ing out my revivifying process, the vat con tents may be exposed freely to the atmosphere in a room and need not be heated or cooled after removal from the decolorizing vats. The gas is thus passed into the mass under ordinary conditions of temperature and pressure. The chlorine gas being shut off as soon as bubbles appear at the surface of the creamy mass, at which time the revivifying process is complete, no special precautions are -needed for the protection of the workers, very little of the gas passing into the atmosphere.

While in many cases, the gas may be passed directly into the spent mass without other treatment, it may be desirable to pre- Wash 1t, particularly where colloidal or other impurities arepresent, which might react with the gas, with which the material is being treated.

I have found that the use of my process renders possible the revivification of the mass several times before it becomes thoroughly. spent and inert.

While the invention has its preferred ap plication in the treatment of decolorizing or purifying activated carbons, it is not limited to-such use, but may be applied to similar treatment of other absorbent carbons, as Well as to decolorizing or purifying agents of other types.

Having thus described my invention, what I claim as new and desire to secure by Letters-Patent ofthe United States is 1. The process of revivifying an absorbent which has been used onv aqueous solutions, which consists in subjecting the same to chlorine gas at a temperature below 100 C.

2. The process of revivifying adecolorizing carbon which has been used on aqueous solutions, which consists in passing chlorine gas thereinto ata temperature below 100 C.

3. The process of revivifyin a solid decolorizing purifying agent, w ichconsists in passing into a wet mass of said agent after previous use thereof, chlorine gas under atmos heric temperature and pressure,

until bubb esof said gas are given off,

4.-.The process of revivifying a, decolori'zthereof, chlorine gas under atmospheric tem rature and ressure until bubbles of sai s are passe ofi. c

5. I he process of revivifying a decoloriz'ing agent, which consists 1n depositing in a vat a mass of said agent after PI'CVIOUS use thereof, with sufiicient li uid to be of a creamy consistency and lea ing chlorine from an ordinary mfiass until bubbles 0 gas begin to be given o V as container into the 6. The process of revivifging a decolor- 15 .conslstency, placing the same in a revivifying vat and leading thereinto commercial ch orlne gas under atmospheric pressure and temperature until bubbles of said gas begin to ass off. igned at New York, in the county of New York and State of New'York, this 14th 2 day of April, A. D. 1926. I

PAUL. MAHLER. 

